Why Do Women With Dementia Outnumber Men 2:1?
Longer female lifespan is only part of the answer. And here is what women can do about it.
Of the 6.2 million people age 65 and older with Alzheimer’s in the United States, two-thirds are women [1]. The question is why.
The most obvious answer (and the one with considerable data to support it) is that Alzheimer risk increases with age, and women tend to live longer than men. The median age at dementia onset in the United States is about 83 years for both men and women. But the average life expectancy for men in the U.S. is 76.1 years. For women, it is 81.1 years [1].
But the story is a little more complicated than that. A study of over 26,000 middle-aged men and women found that women outperform men in this age range on measures of global cognition, executive function, and memory. The problem is that as they age, women suffer significantly faster declines in global cognition and executive function, but not memory. So this means that as women age, they enjoy greater cognitive reserve than men, but when that reserve starts to decline, they suffer a steeper fall-off [2].
Except however, for women who use hormone replacement therapy (HRT) following menopause.
Researchers at the University of Arizona’s College of Medicine and the Center for Innovation in Brain Science investigated dementia risk among 375,000 women aged 45 years and older. They found that HRT was associated with significantly reduced risk of all forms of dementia, including Alzheimer’s disease. And the longer the women had been on HRT, the lower the risk of developing dementia. Important caveat: Not all HRT formulations were equally effective: Natural steroid formulations yielded the greatest protective effects. The greatest reduction in dementia risk was observed in women aged 65 years or older[3].
But what about breast cancer or blood clot risk, you say?
Early studies reported an association between HRT and increased risk of breast cancer and blood clots. But more recent research tells a different story. And that is because of the rise in bioidentical hormones, that is, hormones that are compounded from natural sources that more closely resemble human hormones than do synthesized hormones or hormones extracted from pregnant horses. Synthetic progesterone turns out to be particularly risky. Here are the specific findings:
“Natural” 17 β Estradiol is significantly more effective than conjugated equine estrogen with or without synthetic progestin[4] .
Bioidentical progesterone (micronized) does not increase the risk for deep vein thrombosis (DVT)[4].
Micronized progesterone and dydrogesterone are likely to be associated with a lower risk of breast cancer compared to that seen with other progestogens[5].
Topical estradiol (creams or gels) do not increase the risk of blood clots, whereas the oral synthetic Prempro® does pose that risk [4].
Bio-identical testosterone with and without bio-identical estradiol was found to significantly reduce the risk of breast cancer[6].
Bottom line
Modern HRT seems to be not only safer for postmenopausal women than earlier versions in terms of cancer and blood clot risk, it is also protective against dementia.
[1] https://www.alz.org/media/documents/alzheimers-facts-and-figures.pdf
[2] https://jamanetwork.com/journals/jamanetworkopen/fullarticle/2776902
[3] https://pubmed.ncbi.nlm.nih.gov/34027024/
[4] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8306643/#B17-healthcare-09-00782
[5] https://www.womens-health-concern.org/wp-content/uploads/2021/01/11-WHC-FACTSHEET-HRT-BenefitsRisks-JAN2021-B.pdf
[6] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8306643/
Copyright Denise D. Cummins, PhD Nov 22, 2021
Longer female lifespan is only part of the answer. And here is what women can do about it.
Of the 6.2 million people age 65 and older with Alzheimer’s in the United States, two-thirds are women [1]. The question is why.
The most obvious answer (and the one with considerable data to support it) is that Alzheimer risk increases with age, and women tend to live longer than men. The median age at dementia onset in the United States is about 83 years for both men and women. But the average life expectancy for men in the U.S. is 76.1 years. For women, it is 81.1 years [1].
But the story is a little more complicated than that. A study of over 26,000 middle-aged men and women found that women outperform men in this age range on measures of global cognition, executive function, and memory. The problem is that as they age, women suffer significantly faster declines in global cognition and executive function, but not memory. So this means that as women age, they enjoy greater cognitive reserve than men, but when that reserve starts to decline, they suffer a steeper fall-off [2].
Except however, for women who use hormone replacement therapy (HRT) following menopause.
Researchers at the University of Arizona’s College of Medicine and the Center for Innovation in Brain Science investigated dementia risk among 375,000 women aged 45 years and older. They found that HRT was associated with significantly reduced risk of all forms of dementia, including Alzheimer’s disease. And the longer the women had been on HRT, the lower the risk of developing dementia. Important caveat: Not all HRT formulations were equally effective: Natural steroid formulations yielded the greatest protective effects. The greatest reduction in dementia risk was observed in women aged 65 years or older[3].
But what about breast cancer or blood clot risk, you say?
Early studies reported an association between HRT and increased risk of breast cancer and blood clots. But more recent research tells a different story. And that is because of the rise in bioidentical hormones, that is, hormones that are compounded from natural sources that more closely resemble human hormones than do synthesized hormones or hormones extracted from pregnant horses. Synthetic progesterone turns out to be particularly risky. Here are the specific findings:
“Natural” 17 β Estradiol is significantly more effective than conjugated equine estrogen with or without synthetic progestin[4] .
Bioidentical progesterone (micronized) does not increase the risk for deep vein thrombosis (DVT)[4].
Micronized progesterone and dydrogesterone are likely to be associated with a lower risk of breast cancer compared to that seen with other progestogens[5].
Topical estradiol (creams or gels) do not increase the risk of blood clots, whereas the oral synthetic Prempro® does pose that risk [4].
Bio-identical testosterone with and without bio-identical estradiol was found to significantly reduce the risk of breast cancer[6].
Bottom line
Modern HRT seems to be not only safer for postmenopausal women than earlier versions in terms of cancer and blood clot risk, it is also protective against dementia.
[1] https://www.alz.org/media/documents/alzheimers-facts-and-figures.pdf
[2] https://jamanetwork.com/journals/jamanetworkopen/fullarticle/2776902
[3] https://pubmed.ncbi.nlm.nih.gov/34027024/
[4] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8306643/#B17-healthcare-09-00782
[5] https://www.womens-health-concern.org/wp-content/uploads/2021/01/11-WHC-FACTSHEET-HRT-BenefitsRisks-JAN2021-B.pdf
[6] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8306643/
Copyright Denise D. Cummins, PhD Nov 22, 2021